Raghu, the younger brother of Kanchi mutt's junior Shankaracharya Vijayendra Saraswati, was arrested in Kanchipuram on Thursday night in connection with the Sankararaman murder case, police sources said.
Kanchi seer Jayendra Saraswati is the prime accused in the case.
Raghu was arrested around 2100 IST by the special team investigating the September 3 murder of Sankararaman, a former mutt official.
Mutt lawyer Revathi Vasudevan said Raghu had been charged under Sec 302 (murder), read with Sec 34, 120(b) (conspiracy), of the Indian Penal Code.
With Raghu's arrest, the number of those taken into custody in the case has risen to 24.
Raghu will be produced before a magistrate in Kanchipuram on Friday morning for remand.
The investigating team has already interrogated Raghu, a bachelor, several times this month.
Early this week, the SIT brought him back to Kanchipuram from Chennai, where he was recovering from an appendicitis operation.